JP4518066B2 - Dialkoxynitrile derivative and process for producing the same - Google Patents

Description

  The present invention relates to a dialkoxynitrile derivative useful as, for example, a synthetic raw material for pharmaceuticals and agricultural chemicals and a method for producing the same.

  The dialkoxynitrile derivative of the present invention is a novel compound, and its production method has never been known so far.

  An object of the present invention is to provide a dialkoxynitrile derivative and a method for producing the same.

  The subject of the present invention is

(In the formula, R ¹ represents an alkyl group having 1 to 4 carbon atoms.)
This is solved by dialkoxynitrile derivatives.

  The subject of this invention is also general formula (2) under acidic conditions.

A cyano ketone represented by general formula (3)

(Wherein R ¹ has the same meaning as described above.)
Is reacted with an orthoformate represented by the general formula (1)

(In the formula, R ¹ has the same meaning as described above.)
It can also be solved by the method for producing a dialkoxynitrile derivative according to claim 1 represented by

  According to the present invention, a novel dialkoxynitrile derivative and a method for producing the same can be provided.

  The dialkoxynitrile derivative of the present invention is represented by the general formula (1).

In the general formula (1), R ¹ is an alkyl group having 1 to 4 carbon atoms, specifically, for example, a methyl group, an ethyl group, a propyl group, or a butyl group, preferably a methyl group or an ethyl group. . These include various isomers.

  The dialkoxynitrile derivative is reacted with hydroxylamine and then reacted with an acid to give a general formula (4)

(In the formula, R ¹ and R ² are as defined above.)
Can be led to the 4-substituted-3-aminoisoxazole derivative (described in Reference Example 3 below), and the derived 4-substituted-3-aminoisoxazole derivative can be used as a hypotensive agent or anti-arteriosclerosis. It can be used as a raw material for the synthesis of sulfonamide endothelin antagonist compounds useful as agents (for example, JP-A-6-9585).

  The dialkoxyamide oxime derivative of the present invention can be obtained by reacting an orthoformate represented by the general formula (3) with a cyanoketone represented by the general formula (2) under acidic conditions.

  In the reaction of the present invention, a dialkoxynitrile derivative represented by the general formula (4) is obtained by reacting an orthoformate represented by the general formula (3) with a cyanoketone represented by the general formula (2) under acidic conditions. It is a process.

  The orthoformate used in the reaction of the present invention is represented by the general formula (3), and examples thereof include methyl orthoformate, ethyl orthoformate, propyl orthoformate, isopropyl orthoformate, and butyl orthoformate. Preferably, methyl orthoformate and ethyl orthoformate are used.

  The amount of the orthoformate used is preferably 0.1 to 50 mol, more preferably 0.5 to 10 mol, relative to 1 mol of the cyanoketones.

  The reaction of the present invention is carried out under acidic conditions. In order to make the reaction system acidic, an acid is present in the system. Examples of the acid used include mineral acids such as hydrochloric acid, sulfuric acid and phosphoric acid; sulfonic acids such as benzenesulfonic acid and p-toluenesulfonic acid; acetic acid Carboxylic acids such as propionic acid and butyric acid are preferable, and mineral acids and sulfonic acids are preferably used. In addition, you may use these acids individually or in mixture of 2 or more types.

  The amount of the acid used is not particularly limited as long as it makes the reaction system acidic, but is preferably 0.001 to 10 mol, more preferably 0.005 to 5 mol, with respect to 1 mol of the cyanoketones.

  The reaction of the present invention is carried out in the presence or absence of a solvent. The solvent used is not particularly limited as long as it does not participate in the reaction. For example, cycloaliphatic hydrocarbons such as cyclohexane, cycloheptane and cyclooctane; aromatic hydrocarbons such as toluene, xylene and cumene; chlorobenzene, Halogenated aromatic hydrocarbons such as bromobenzene; nitrated aromatic hydrocarbons such as nitrobenzene; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, etc. Carboxylic acid esters of: alcohols such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, t-butyl alcohol, preferably cyclic aliphatic hydrocarbons, aromatic Used by hydrocarbons, carboxylic acid esters, and alcohols It is. In addition, you may use these solvents individually or in mixture of 2 or more types.

  The amount of the solvent used is appropriately adjusted depending on the uniformity and agitation of the solution, but is preferably 0.5 to 100 ml, more preferably 1 to 50 ml with respect to 1 g of cyanoketones.

  The reaction of the present invention is performed by, for example, a method of mixing an acid, a cyano ketone, an orthoformate ester and a solvent in an inert gas atmosphere and stirring. The reaction temperature at that time is preferably 0 to 200 ° C., more preferably 5 to 160 ° C., and the reaction pressure is not particularly limited.

  The dialkoxynitrile derivative obtained by the reaction of the present invention is treated by a general method such as recrystallization, distillation, column chromatography, etc. after the reaction is completed, for example, after neutralization, extraction, concentration, filtration, etc. It can be isolated and purified.

  Next, the present invention will be specifically described with reference to examples, but the scope of the present invention is not limited thereto.

Reference Example 1 (Synthesis of sodium salt of 3-cyano-2-butanone)
In a glass flask having an internal volume of 300 ml equipped with a stirrer, thermometer and reflux condenser, sodium methoxide 13.0 g (0.24 mol), propionitrile 19.9 g (0.36 mol), n-butyl acetate 37.2 g (0.32 mol) ) And 100 ml of toluene, and reacted at 90 ° C. for 24 hours in a nitrogen atmosphere. After completion of the reaction, the reaction mixture was cooled to room temperature, and the precipitate was filtered and dried to obtain 12.0 g of a sodium salt of 3-cyano-2-butanone as a colorless powder (isolation yield; 41.7%).
The physical properties of sodium salt of 3-cyano-2-butanone were as follows.

¹ H-NMR (DMSO-d ₆ , δ (ppm)); 1.45 (3H, s), 1.75 (3H, s)

Reference Example 2 (Synthesis of 3-cyano-2-butanone)
To a glass flask having an internal volume of 300 ml, 30.0 g (0.25 mol) of sodium salt of 3-cyano-2-butanone synthesized in the same manner as in Reference Example 1, 40 ml of water and 100 ml of ethyl acetate were added. Next, after adding 21.7 ml (0.26 mol) of concentrated hydrochloric acid, the organic layer was taken out and dried over anhydrous magnesium sulfate. After filtration, the filtrate was concentrated under reduced pressure to obtain 22.3 g of 3-cyano-2-butanone as a colorless liquid (isolated yield; 92%).
The physical properties of 3-cyano-2-butanone were as follows.

¹ H-NMR (DMSO-d ₆ , δ (ppm)); 1.50 (3H, d), 2.38 (3H, s), 3.60 (1H, q)

Example 1 (Synthesis of 2-methylbutyronitrile-3-one-diethylacetal)
Concentrated sulfuric acid 10 mg (0.1 mmol), 1.94 g (24 mmol) 3-cyano-2-butanone synthesized in the same manner as in Reference Example 2, orthoformatic acid in a glass flask with an internal volume of 25 ml equipped with a stirrer and a thermometer Ethyl 3.56 g (24 mmol) and ethanol 5 ml were added, and the mixture was reacted at room temperature for 7 hours in a nitrogen atmosphere. After completion of the reaction, 0.75 g (5 mmol) of potassium carbonate was added to the reaction solution, and the mixture was further stirred at room temperature for 1 hour. The precipitate was filtered and the filtrate was concentrated under reduced pressure to give 2.91 g of 2-methylbutyronitrile-3-one-diethylacetal as a pale yellow liquid (isolated yield; 85%).
2-Methylbutyronitrile-3-one-diethylacetal is a novel compound represented by the following physical property values.

¹ H-NMR (CDCl ₃ , δ (ppm)); 1.0 to 1.3 (9H, m), 1.40 (3H, s), 3.2 to 3.6 (4H, m), 4.10 (1H, q)

Example 2 (Synthesis of 2-methylbutyramideoxime-3-one-diethylacetal)
1.46 g (36.5 mmol) of sodium hydroxide, 7 ml of water and 1.97 g (28.3 mmol) of hydroxylamine hydrochloride were mixed in a glass flask having an internal volume of 25 ml equipped with a stirrer, thermometer, dropping funnel and reflux condenser. Under ice-cooling, a solution of 2.40 g (14.0 mmol) of 2-methylbutyronitrile-3-one-diethylacetal synthesized in the same manner as in Example 1 was slowly dropped into 7 ml of methanol, and a nitrogen atmosphere was added. The mixture was reacted at 10 ° C. for 2 hours, at room temperature for 13 hours, and further heated under reflux (70 to 75 ° C.) for 1.5 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted three times with 20 ml of ethyl acetate. The organic layer was taken out and dried over anhydrous magnesium sulfate. After filtration, the filtrate was concentrated under reduced pressure to obtain 2.45 g of 2-methylbutylamidooxime-3-one-diethylacetal as a pale yellow liquid (isolation yield; 86%).
2-Methylbutlamidooxime-3-one-diethylacetal is a novel compound represented by the following physical property values.

¹ H-NMR (CDCl ₃ , δ (ppm)); 1.1 to 1.3 (9H, m), 1.40 (3H, s), 2.8 to 3.2 (1H, m), 3.2 to 4.3 (5H, m), 5.0 to 5.2 (2H, brs)

Reference Example 3 (Synthesis of 3-amino-4,5-dimethylisoxazole)
In a glass flask equipped with a stirrer and a thermometer and having an internal volume of 25 ml, 2.25 g (11 mmol) of 2-methylbutamidooxime-3-one-diethylacetal synthesized in the same manner as in Example 2, ethanol 13 ml and concentrated 20 mg (0.2 mmol) of sulfuric acid was added, and the mixture was reacted at room temperature for 15 hours in a nitrogen atmosphere. After completion of the reaction, the reaction mixture was concentrated under reduced pressure, and the concentrate was recrystallized from 1 ml of isopropyl alcohol to obtain 1.00 g of 3-amino-4,5-dimethylisoxazole as a white powder (isolated yield; 81%) .
The physical properties of 3-amino-4,5-dimethylisoxazole were as follows.

¹ H-NMR (CDCl ₃ , δ (ppm)); 1.80 (3H, s), 2.20 (3H, s), 3.80 (2H, s)

Example 3 (Synthesis of 2-methylbutyronitrile-3-one-dimethylacetal)
In a glass flask equipped with a stirrer and a thermometer and having an internal volume of 50 ml, 10 mg (0.1 mmol) of concentrated sulfuric acid, 7.14 g (73.5 mmol) of 3-cyano-2-butanone synthesized in the same manner as in Reference Example 2, 15.6 g (147 mmol) of methyl acid and 30 ml of methanol were added, and the mixture was reacted at room temperature for 23 hours in a nitrogen atmosphere. After completion of the reaction, 1.02 g (6.8 mmol) of potassium carbonate was added to the reaction solution, and the mixture was further stirred at room temperature for 1 hour. The precipitate was filtered, the filtrate was concentrated under reduced pressure, and the concentrate was subjected to silica gel column chromatography (filler; Wako Gel C-200 (manufactured by Wako Pure Chemical Industries, Ltd.), developing solvent; n-hexane / ethyl acetate = 3 / 1 (volume ratio)) to give 9.5 g of 2-methylbutyronitrile-3-one-dimethylacetal as a pale yellow liquid (isolation yield; 90%).
2-Methylbutyronitrile-3-one-dimethyl acetal is a novel compound represented by the following physical property values.

¹ H-NMR (CDCl ₃ , δ (ppm)); 1.23 (3H, d), 1.40 (3H, s), 3.02 (1H, q), 3.17 (3H, s), 3.28 (3H, s)

Example 4 (Synthesis of 2-methylbutyramideoxime-3-one-dimethylacetal)
Hydroxylamine hydrochloride 3.48 g (50.0 mmol) and methanol 10 ml were mixed in a glass flask having an internal volume of 50 ml equipped with a stirrer, thermometer, dropping funnel and reflux condenser, and triethylamine 6.33 g (62.6 mmol), and a solution prepared by dissolving 3.58 g (25.0 mmol) of 2-methylbutyronitrile-3-one-dimethylacetal synthesized in the same manner as in Example 3 in 5 ml of methanol was gradually and gradually dropped into a nitrogen atmosphere. And reacted for 8 hours under heating and reflux (60 to 64 ° C.). After completion of the reaction, the reaction mixture was cooled to room temperature, concentrated under reduced pressure, and 120 ml of ethyl acetate and 40 ml of water were added to the concentrate. Next, the organic layer was taken out and dried over anhydrous magnesium sulfate. After filtration, the filtrate was concentrated under reduced pressure to obtain 3.15 g of 2-methylbutlamidooxime-3-one-dimethylacetal as a colorless powder (isolation yield: 72%).
2-Methylbutlamidooxime-3-one-dimethylacetal is a novel compound represented by the following physical property values.

¹ H-NMR (CDCl ₃ , δ (ppm)); 1.12 (3H, d, J = 7.1 Hz), 1.25 (3H, s), 2.73 (1H, q, J = 7.1 Hz), 3.20 (1H, brs ), 3.21 (3H, s), 3.26 (3H, s), 5.03 (2H, br)

Reference Example 4 (Synthesis of 2-formylbenzylcyanide)
In a glass flask having an internal volume of 200 ml equipped with a stirrer, a thermometer and a reflux condenser, sodium methoxide 8.1 g (0.15 mol), benzyl cyanide 17.6 g (0.15 mol), ethyl formate 12.3 g (0.17 mol) and 70 ml of methanol was added and reacted at room temperature in a nitrogen atmosphere for 6 hours. After completion of the reaction, a solid was precipitated, and was filtered and dried. This solid was dissolved in 200 ml of water, and 5.8 ml (70 mol) of concentrated hydrochloric acid was added. The precipitated crystals were filtered and dried to obtain 9.0 g of 2-formylbenzylcyanide as a colorless powder (isolation yield: 41%).
The physical properties of 2-formylbenzylcyanide were as follows.

¹ H-NMR (DMSO-d ₆ , δ (ppm)); 7.32-7.70 (6H, m), 8.06 (1H, s)

Example 5 (Synthesis of 2- (β-diethoxyformyl) benzyl cyanide)
In a 100 ml glass flask equipped with a stirrer and a thermometer, 10 mg (0.1 mmol) of concentrated sulfuric acid, 5.81 g (40 mmol) of 2-formylbenzylcyanide synthesized in the same manner as in Reference Example 4, methyl orthoformate 17.76 g (120 mmol) and 40 ml of ethanol were added and reacted at room temperature for 15 hours in a nitrogen atmosphere. After completion of the reaction, 4.0 g (5 mmol) of potassium carbonate was added to the reaction solution, and the mixture was further stirred at room temperature for 1 hour. The precipitate was filtered, the filtrate was concentrated under reduced pressure, and the concentrate was subjected to silica gel column chromatography (filler; Wako Gel C-200 (manufactured by Wako Pure Chemical Industries, Ltd.), developing solvent; n-hexane / ethyl acetate = 4 / 1 (volume ratio)) to obtain 4.1 g of 2- (β-diethoxyformyl) benzyl cyanide as a colorless powder (isolation yield; 47%).
The physical properties of 2- (β-diethoxyformyl) benzyl cyanide were as follows.

¹ H-NMR (CDCl ₃ , δ (ppm)); 1.09 (3H, t), 1.22 (3H, t), 3.30 to 3.80 (4H, m), 4.00 (2H, d), 4.62 (2H, d) 7.30-7.41 (5H, m)

Example 6 (Synthesis of 2- (β-diethoxyformyl) -2-phenylacetamidooxime)
Hydroxylamine hydrochloride 695 mg (10 mmol) and methanol 5 ml were mixed in a glass flask having an internal volume of 25 ml equipped with a stirrer, thermometer, dropping funnel and reflux condenser, and 1.52 g (15 mmol) of triethylamine under ice cooling, A solution prepared by dissolving 1.1 g (5 mmol) of 2- (β-diethoxyformyl) benzylcyanide synthesized in the same manner as in Example 5 in 1 ml of methanol was gradually added dropwise and heated under reflux in a nitrogen atmosphere. (60 to 64 ° C.) for 4 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, concentrated under reduced pressure, and 30 ml of ethyl acetate and 3 ml of a saturated aqueous sodium hydrogen carbonate solution were added to the concentrate. Next, the organic layer was taken out and dried over anhydrous magnesium sulfate. After filtration, the filtrate was concentrated under reduced pressure, and the concentrate was subjected to silica gel column chromatography (filler; Wako Gel C-200 (manufactured by Wako Pure Chemical Industries, Ltd.), developing solvent; n-hexane / ethyl acetate = 1/2 (volume) Ratio)) to give 0.8 g of 2- (β-diethoxyformyl) -2-phenylacetamidooxime as a colorless powder (isolation yield; 64%).
2- (β-Diethoxyformyl) -2-phenylacetamidooxime is a novel compound represented by the following physical property values.

¹ H-NMR (CDCl ₃ , δ (ppm)); 1.12 (3H, t, J = 7.1 Hz), 1.20 (3H, t, J = 7.1 Hz), 3.50 to 3.85 (5H, m), 4.84 (1H , d, J = 4.9Hz), 5.03 (2H, br), 7.25-7.45 (6H, m)

  The present invention relates to a dialkoxynitrile derivative useful as, for example, a synthetic raw material for pharmaceuticals and agricultural chemicals and a method for producing the same.

Claims (4)

General formula (1)

(In the formula, R ¹ represents an alkyl group having 1 to 4 carbon atoms.)
A dialkoxynitrile derivative represented by: The dialkoxynitrile derivative according to claim 1, wherein R ¹ is a methyl group or an ethyl group. Under acidic conditions, general formula (2)

A cyano ketone represented by general formula (3)

(Wherein R ¹ has the same meaning as described above.)
Is reacted with an orthoformate represented by the general formula (1)

(In the formula, R ¹ has the same meaning as described above.)
A process for producing a dialkoxynitrile derivative according to claim 1,   The method for producing a dialkoxynitrile derivative according to claim 3, wherein the orthoformate is methyl orthoformate or ethyl orthoformate.